METHOD FOR PRODUCING TUBE AND APPARATUS FOR PERFORMING THE SAME, APPARATUS FOR OBTAINING INFORMATION RELATED TO TUBE THICKNESS FLUCTUATION AND COMPUTER PROGRAM

摘要

FIELD: metallurgical production processes. ^ SUBSTANCE: method comprises steps of using complex Fourier transform while using measured thickness values in cross section of tube in different portions along tube length; sorting type of tube wall thickness variations while counting number of said variation according to absolute values of complex Fourier components; determining location of tube portions with thin wall or with thick wall while taking into account phases of complex Fourier components. Conditions of tube production process are controlled on base of type of tube wall thickness variations, total number of variations and locations of tube portions with thin or thick wall. Relationship between value of tube wall thickness at primary change of wall thickness obtained for cross section along lengthwise axis and for given phase is subjected to complex Fourier transform depending upon tube length direction. Tube wall thickness variations are classified in addition according to frequency of said variations. Respective working operations are performed according to classified wall thickness variations in order to prevent them. ^ EFFECT: lowered values of tube wall thickness fluctuations. ^ 24 cl, 10 dwg